1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method and a program.
2. Description of the Related Art
When an image is shown on a display, if the image is a wide dynamic range image or a high-contrast image, there may be generated a part having a small brightness difference and a low contrast so that the image on the display is unclear, as shown in FIG. 6A. For example, the brightness difference between an outdoor environment and a person therein as shown in FIG. 6A may be small and the brightness difference between an indoor environment and a person therein as shown in FIG. 6A may be small. The phenomenon of an unclear image caused by a small brightness difference occurs in both a light area and a dark area. FIGS. 6A and 6B are explanatory diagrams showing examples of an image.
To improve the contrast of a part having a small brightness difference, a tone correction is performed on the image in general. A related technique of a tone correction is described in, for example, Frédo Durand and Julie Dorsey, Fast Bilateral Filtering for the Display of High-Dynamic-Range Images, In SIGGRAPH '02: Proceedings of the 29th annual conference on Computer graphics and interactive techniques (2002), pp. 257-266. In the technique of the above document, a tone correction is performed on each area or each pixel of a wide dynamic range image.